Visible multiple fuse



F 1935- AQJ. MATTER VISIBLE MULTIPLE FUSE Filed Aug. 22, 1933 ZI JTNESS:

JN ENTQH;

/wm Q Patented Feb. 5, 1935 UNITED STATES PATENT OFFICE 17 Claims.

My invention relates to improvements in electrical fuses of the multiple type with visible fusible elements and has for its object to provide a simple construction inexpensive to manufacture and easy to assemble. Another object is to provide proper venting for the gases when a fusible member is blown and means for readily connecting another fusible member in the circuit. Another object is to provide readily discernible indications of which fusible elements have been blown or disrupted. I r

I attain these objects by means of the constructionillustrated in the accompanying drawing, in which,

Fig. 1 is an elevation, partly in cross section Fig. 2 is a top view of the fuse shown in Fig. 1.

Fig. 3 is a top view of the fuse with the rotatable member '7 removed as shown in the left half of the view and with the head 5 also shown removed in the right half of the view. The mica 6 is also omitted in this figure.

Fig. 4 shows a bottom view of the rotatable member 7 with optional vents indicated.

Fig. 5 is a top view of the case 1 and shows a modified form of spring contact.

Fig. 6 shows a fragmental sectional elevation illustrating a modified form of venting means.

Similar numerals refer to similar parts throughout the several views.

Referring to Figures 1, 3 and 5 an insulating case cup-shaped as shown at 1 is provided with dovetailed grooves 1a in the inner wall 1b and an orifice through the bottom at 1c. The case 1 is also provided with an annular shoulder at 1d. Three fusible elements are shown at 3 but it is to be understood that this number may be increased or decreased if desired without affecting the spirit of the invention. These elements 3 are disposed with one end of each extending downwardly into the dovetailed grooves in of case 1 and have the opposite ends bent outwardly and over the edge of the cup-shaped case 1 and thence downwardly along the outer wall of the case. In order to provide for easy insertion of the fusible elements into the dovetailed grooves in case 1 it may be found desirable to round off the top edges of the grooves as shown at In in Figure 5 and also indicated in Figure 1 wherein the rim of the case is slightly depressed to an extent equal to the width. of the grooves. This also provides a recess for the uppermost portions of the fusible elements so that they may be disposed flush with the upper rim of the case 1,

A threaded metal screw-shell 4 having a reduced cylindrical collar 4b and provided with a plurality of raised lugs 4a is disposed so that the collar 4b fits snugly around the outer ends of the fusible elements 3 and rests against the shoulder of the case at 1d.

5 indicates the head of the fuse and is made of insulating material. It is provided with an enlarged portion at 5a forming an annular rim which is recessed as at 5 to provide an enclosed space for a rotatable member. The inner wall 5b of the head 5 is adapted to flt closely around the fusible elements 3 and it is counterbored at 50 to fit snugly around the collar 4b of the screwshell 4. The bottom edge of head 5 is provided with one or more notches 5d adapted to engage lugs 4a on the screw-shell.

Head 5 is further provided with a raised annular ridge 5e which is shown provided with vent grooves 59.

6 indicates a circular mica disc with a perforation in the center and rests upon the ridge or inner shoulder 5e of head 5 as shown;

A rotatable member 7 is provided with an annular flange 7a surrounding a disc-shaped portion and extending upwardly. Another annular flange 7b extends downwardly from the discshaped portion and may be provided with vent grooves as indicated at 7c in Figure 4. Although only three vents 7c are shown it is intended to provide such vents all around the flange 7b in such cases where they are employed at all. In my preferred construction these vents '70 would be omitted.

The rotatable member 7 is further provided with a coaxial cylindrical projection if having an orifice 7g which is counterbored at 71' and Tia: and is provided with a slot at 7h. 7e indicates raised lugs provided on the top of rotatable member 7 to facilitate turning it. Member 7 is also provided with a sight opening at 'ld, and is disposed with the flanged disc-shaped portion rotatably free within the enlarged annular rim 5a of head 5 and resting upon the mica disc 6 and with the cylindrical projection 7f extending through the central oriflce in the mica disc as shown in Figure 1.

I prefer to form the rotatable member 7 so as to exert a slight pressure downwardly upon the inner edge of the mica disc 6 by extending downwardly the under side of the disc-shaped portion adjacent to the cylindrical extension 7! as shown in Figure 6 and leaving a small space between the periphery of the mica disc 6 and the under side of member 7. This arrangement permits the mica disc to act as a valve to relieve excess internal pressure when a fuse is blown. This method of venting may be used with or without additional vents 5g as shown in Figures 1 and 6.

The terms upwardly and downwardly as used herein have reference to the position of the parts as disposed in Figures 1 and 6 and are used merely to facilitate description and not to indicate the position in which the fuse or its parts are disposed when in operation.

To hold the various parts of the fuse together and in operable relationship I provide a headed rivet 2 which is disposed within the orifice 1c of case 1 and passes through counterbore 'Iiz, orifice 7g and into counterbore 72' of head-end of the rotatable member 7 where it is riveted over to form a head 2a just tight enough to exert a slight pressure upon the mica disc as previously described.

To complete the electrical circuit between the rivet and the inner ends of the fusible members 3, one at a time, I provide a spring contact member 8 having a cylindrical part 8a disposed around the rivet 2 and having extensions 80 and 8d adapted to engage the sides of slot 7h of the rotatable member 7. The spring is preferably U-shaped with sufiicient outward tension against the fusible element 3 to provide good electrical contact. 821 indicates an inwardly disposed lip on spring contact 8 to facilitate clockwise rotation of the spring contact about its axis as it passes into and out of grooves 1a. A modified form of spring contact is shown at 8.1: in Figure 5.

Rotation of member '7 successively brings into view the several fusible elements 3 through the sight opening 7d, thus indicating which of said fusible elements at the time are in the electrical circuit and further indicating when it is blown.

Venting of gases caused by blowing of the fusible element is permitted by outward flexing of the perimeter of the mica disc and the gases then pass through the space between the rotatable member 7 and the head 5, emerging at V.

What I claim is;

l. A fuse comprising a cup-shaped insulating case having av central orifice, a rivet extending through said orifice, a plurality of fusible elements disposed over the rim of said case with one end of each extending into the case and their opposite ends extending along the outer wall of the case, a threaded metallic screw-shell surrounding the outer ends of said fusible members and in contact therewith, an insulating head having an annular rim and disposed against said screw-shell in looking engagement therewith, a metallic spring contact mounted on said rivet and adapted for successive engagement with each of the several'fusible elements, a transparent disk having a central orifice and disposed within the annular rim of the aforesaid insulating head, and a-rotatable member of disk form with a cylindrical extension and provided with a sight opening through said disk-shaped portion and means in said cylindrical extension adapted to engage said spring contact, the aforesaid rotatable member being disposed with the disk-shaped portion rotatable within the rim of the head and against the transparent disk and its cylindrical extension passing through the orifice in the transparent disk in operable engagement with the spring contact and surrounding the rivet in such manner that all of the parts are held in operable relation thereby.

case having an annular external shoulder and a central orifice and provided with a plurality of grooves in the internal wall of the case, a rivet disposed through said orifice, a plurality of fusible elements disposed over the rim of said case with one end of each extending into said grooves and their opposite ends extending along the outer Wall of the case, a threaded metallic screw-shell surrounding the outer ends of said fusible members and in contact therewith and resting on the annular external shoulder of said case, an insulating head having an annular rim and disposed against said screw-shell in locking engagement therewith, a metallic spring contact mounted on said rivet and adapted for successive engagement with each of the several fusible elements, a transparent disk having a'central orifice and disposed within the annular rim of the aforesaid insulating head, and a rotatable member of disk form with a cylindrical extension and provided with a sight opening through said disk-shaped portion and means in said cylindrical extension adapted to engage said spring contact, the aforesaid rotatable member being nisposed with the disk-shaped portion rotatable within the rim of the head and against the transparent disk and its cylindrical extension passing through the orifice in the transparent disk in operable engagement with the spring contact and surrounding the rivet in such manner that all of the parts are held in operable relation thereby.

3. A fuse comprising a cup-shaped insulating case having a central orifice, a rivet extending through said orifice, a plurality of fusible elements disposed over the rim of said case with one end of each extending into the case and their opposite ends extending along the outer wall of the case, a threaded metallic screw-shell having raised lugs, surrounding the outer ends of said fusible members and in contact therewith, an insulating head having an annular rim and provided with notches adapted to engage the raised lugs on said screw-shell, a metallic spring contact mounted on said rivet and adapted for successive engagement with each of the several fusible elements, a transparent disk having a central orifice and disposed within the annular rim of-the aforesaid insulating head, and a rotatable member of disk form with a cylindrical extension and provided with a sight opening through said disk-shaped portion and means in said cylindrical extension adapted to engage said spring contact, the aforesaid rotatable member being disposed with the disk-shaped portion rotatable within the rim of the head and against the transparent disk, and its cylindrical extension passing through the orifice in the transparent disk in operable engagement with the spring contact and surrounding the rivet in such manner that all of the parts are held in operable relation thereby.

4. A fuse comprising a cup-shaped insulating case having a central orifice, a rivetextending through said orifice, a plurality of fusible elements disposed over the rim of said case with one end of each extending into the case and their opposite ends extending along the outer walls of the case, a threaded metallic screw-shell surrounding the outer ends of said fusible members and in contact therewith, an insulating head having an annular rim and'disposed against said screw-shell in looking engagement therewith, a U-shaped metallic spring contact mounted on said rivet and adapted for successive engagement with each of the several fusible elements, a transparent disk having a central orifice and disposed within the annular rim of the aforesaid insulating head, and a rotatable member of disk form with a'cylindrical extension and provided with a sight opening through said disk-shaped portion and means in said cylindrical extension adapted to engage said spring contact, the aforesaid rotatable member being disposed with the diskshaped portion rotatable within the rim of the head and against the transparent'disk, and its cylindrical extension passing through the orifice in the transparent disk in operable engagement with the spring contact and surrounding the rivet in such manner that all of the parts are held in operable relation thereby.

5. A fuse comprising a cup-shaped case having a central orifice, a rivet extending through said orifice, a plurality of fusible elements disposed Over the rim of said case with one end of each extending into the case and their opposite ends extending along the outer wall of the case, a threaded metallic screw-shell surrounding the outer ends of said fusible members and-in contact therewith, an insulating head having an annular rim and'disposed against said screw-shell in locking engagement therewith, a U-shaped metallic spring contact having transverse extensions at the upper ends of the U and mounted on said rivet and adapted for successive engagement with each of the several fusible members, a transparent disk having a central orifice and disposed within the annular rim of the aforesaid insulating head, and a rotatable member of disk form with a cylindrical extension and provided with a sight opening through said disk-shaped portion and means in said cylindrical extension adapted to engage said spring contact, the aforesaid rotatable member being disposed with the diskshaped portion rotatable within the rim of the head and against the transparent disk, and its cylindrical extension passing through the orifice in the transparent disk in operable engagement with the spring contact and surrounding the rivet in such manner that all of the parts are held in operable relation thereby.

6. A fuse comprising a cup-shaped insulating case having a central orifice, a. rivet extending through said orifice, a plurality of fusible elements disposed over the rim of said case with one end of each extending into the case and their opposite ends extending along the outer wall of the case, a threaded metallic screw-shell surrounding the outer ends of said fusible members and in contact therewith, an insulating head having an annular rim and disposed against said screwshell in looking engagement therewith, a metallic spring contact mounted on said rivet and adapted for successive engagement with each of the several fusible elements, a flexible transparent disk having a. central orifice and disposed within the annular rim of the aforesaid insulating head, so as to provide a fiexible vent at the periphery of the disk, and a rotatable member of disk form with a cylindrical extension and provided with 'a sight opening through said disk-shaped portion and means in said cylindrical extension adapted to engage said spring contact, the aforesaid rotatable member being disposed with the diskshaped portion rotatable within the rim of the head and against the transparent disk, and its cylindrical extension passing through the orifice in the transparent disk in operable engagement with the spring contact and surrounding the rivet in such manner that all of the parts are held in operable relation thereby.

7. A fuse comprising a cup-shaped insulating case having a central orifice, a rivet extending through said orifice, a plurality of fusible elements disposed over the rim of said case with one end of each extending into the case and their opposite ends extending along the outer wall of the case, a threaded metallic screw-shell surrounding the outer ends of said fusible members and in contact therewith, an insulating head having an annular rim and an annular raised ridge of lesser diameter than said rim and provided with means for interlocking engagement with said screw-shell, a metallic spring contact mounted on said rivet and adapted for successive engagement with each of the several fusible elements, a transparent disk having a central orifice and disposed within the annular rim of the aforesaid insulating head and against the raised ridge thereof, and a rotatable member of disk form with a cylindrical extension and provided with a sight opening through said disk-shaped portion and means in said cylindrical extension adapted to engage said spring contact, the aforesaid rotatable member being disposed with the disk-shaped portion rotatable within the rim of the head and against the transparent disk, and its cylindrical extension passing through the orifice in the transparent disk in operable engagement with the spring contact and surrounding the rivet in such manner that all of the parts are held in operable relation thereby.

8. A fuse comprising a cup-shaped insulating with said screw-shell, a metallic spring contact mounted on said rivet and adapted for successive engagement with each of the several fusible elements, a transparent disk having a central orifice and disposed within the annular rim of the aforesaid head and against the raised ridge thereof, and a rotatable member of disk form with a cylindrical extension and provided With a sight opening through said disk-shaped portion and means in said cylindrical extension adapted to engage said spring contact, the aforesaid rotatable member being disposed with the disk-shaped portion rotatable within the rim of the head and against the transparent disk, and its cylindrical extension passing through the orifice in the transparent disk in operable engagement with the spring contact and surrounding the rivet in such manner that all of the parts are held in operable relation thereby.

9. A fuse comprising a cup-shaped insulating case having a central orifice, a rivet extending through said orifice, a plurality of fusible elements disposed over the rim of said case with one end of each extending into the case and their opposite ends extending along the outer wall of the case, a threaded metallic screw-shell surrounding the outer ends of said fusible member and in contact therewith, an insulating head having an annular rim and disposed against -said screw-shell in locking engagement therewith, a

metallic spring contact mounted on said rivet and adapted for successive engagement with each of the several fusible elements, a transparent disk having a central orifice and disposed within the annular rim of the aforesaid insulating head, and a rotatable member of disk form having an annular flange and a cylindrical extension and provided with a sight opening through said diskshaped portion and means in said cylindrical extension adapted to engage said spring contact, the aforesaid rotatable member being disposed with the disk-shaped portion rotatable within the rim of the head and against the transparent disk and its cylindrical extension passing through the orifice in the transparent disk in operable engagement with the spring contact and surrounding the rivet in such manner that all of the parts are held in operable relation thereby. I

10. A fuse comprising a cup-shaped insulating case having a central orifice, a rivet extending through the orifice. a plurality of fusible elements disposed over the rim of said case with one end of each extending into the case and their opposite ends extending along the outer wall of the case, a threaded metallic screw-shell surrounding the outer ends of said fusible members and in contact therewith, an insulating head having an annular rim and disposed against said screw-shell in locking engagement therewith, a metallic spring contact mounted on said rivet and adapted for successive engagement with each of the several fusible elements, a transparent disk having a central orifice and disposed within the annular rim of the aforesaid insulating head, and a rotatable member of disk form having an annular radially grooved flange and a cylindrical extension and provided with a sight opening through said disk-shaped portion and means in said cylindrical extension adapted to engage said spring contact, the aforesaid rotatable member being disposed with the disk-shaped portion rotatable within the rim of the insulating head and against the transparent disk, and its cylindrical extension passing through the orifice in the transparent disk in operable engagement with the spring contact and surrounding the rivet in such manner that all of the parts are held in operable relation thereby.

11. In a fuse comprising an insulating case, a threaded metallic screw-shell, a plurality of fusible elements in contact with said screw-shell, a metallic central contact pin and a metallic contacting member mounted on said pin and engageable with said fusible elements, the combination therewith of a rotatable insulating member having a disk-shaped head with a cylindrical coaxial elongated extension adapted to engage and rotate said contacting member into and out of electrical contact with the several fusible elements and provided with a sight opening through said disk-shaped portion.

12. In a fuse comprising an insulating case, a threaded metallic screw-shell, a pluralityof fusible elements in contact with said screw-shell, a metallic central contact pin and a metallic contacting member mounted on said pin and engageable with said fusible elements, the combination therewith of a rotatable insulating member having a disk-shaped head with acylindrical co-axial elongated extension adapted to engage and rotate said contacting member into and out of electrical contact with the several fusible elements and provided with an annular.flange having vent groovesadjacent the rim of said diskshaped head and disposed in the same direction as the cylindrical extension aforementioned.

13. In a fuse, the combination with a rotatable contacting member, a central contact pin, an insulating case, a plurality of fusible elements, and a ring-shaped insulating head having notches, of a threaded, screw-shell having. raised lugs adapted to engage said notches.

14. In a fuse, the combination with a rotatable contacting member having a disk-shaped head, a cup-shaped insulating case having an annular external shoulder, fusible elements, and a central rivet adapted to hold said rotatable member in operable position opposite the open end of the cup-shaped case, of a threaded metallic screwshell and a ring-shaped insulating head disposed between the annular shoulder of the cup-shaped case and the disk-shaped head of the rotatable contacting member.

15. In a fuse, the combination with a rotatable contacting member having a disk-shaped head, a cup-shaped insulating case having an annular external shoulder, fusible elements, and a central rivet adapted to hold said rotatable member in operable position opposite the open end of the cup-shaped case, of a threaded metallic screwshell and a ring-shaped insulating head provided with interlocking means and disposed between.

the annular shoulder of the cup-shaped case and the disk-shaped head of the rotatable contacting member.

16. In a fuse comprising a cup-shaped insulating case, a plurality of fusible elements, mounted in said case, a threaded metallic screw-shell disposed around said case, a central contact pin,

a contacting member operably disposed between said pin and one of said fusible elements, the combination therewith of a ring-shaped insulating head having an annular rim and a raised annular ridge within said rim, a flexible transparent disk disposed against said ridge and having a central orifice, and a rotatable insulating member having a sight opening and disposed to engage and depress the orifice periphery of the flexible transparent disk, all substantially asdescribed.

17. In a fuse comprising a cup-shaped insulating case, a plurality of fusible elements mounted in said case, a threaded metallic screw-shell disposed around said case, a central contact pin, a contacting member operably disposed between said pin and one of said fusible elements, the combination therewith of a ring-shaped insulating head having an annular rim and-a raised annular ridge with ventgrooves within. said rim. a flexible transparent disk disposed against said ridge and having a central orifice, and a rotatable insulating member having a sight opening and disposed to engage and depress the orifice periphery of the flexible transparent disk, all substantially as described.

ALBERT J. MATTER. 

